mtd: spi-nor: Fix shift-out-of-bounds in spi_nor_set_erase_type

commit f0f0cfdc3a024e21161714f2e05f0df3b84d42ad upstream.

spi_nor_set_erase_type() was used either to set or to mask out an erase
type. When we used it to mask out an erase type a shift-out-of-bounds
was hit:
UBSAN: shift-out-of-bounds in drivers/mtd/spi-nor/core.c:2237:24
shift exponent 4294967295 is too large for 32-bit type 'int'

The setting of the size_{shift, mask} and of the opcode are unnecessary
when the erase size is zero, as throughout the code just the erase size
is considered to determine whether an erase type is supported or not.
Setting the opcode to 0xFF was wrong too as nobody guarantees that 0xFF
is an unused opcode. Thus when masking out an erase type, just set the
erase size to zero. This will fix the shift-out-of-bounds.

Fixes: 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories")
Cc: stable@vger.kernel.org
Reported-by: Alexander Stein <Alexander.Stein@tq-group.com>
Signed-off-by: Louis Rannou <lrannou@baylibre.com>
Tested-by: Alexander Stein <Alexander.Stein@tq-group.com>
Link: https://lore.kernel.org/r/20230203070754.50677-1-tudor.ambarus@linaro.org
[ta: refine changes, new commit message, fix compilation error]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index d5dcc74a625ed478886bf47be91aac4fb856de06..1e61c2364622f7c7d0c99c7f073756ed87389036 100644 (file)
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -2246,6 +2246,15 @@ void spi_nor_set_erase_type(struct spi_nor_erase_type *erase, u32 size,
        erase->size_mask = (1 << erase->size_shift) - 1;
 }
 
+/**
+ * spi_nor_mask_erase_type() - mask out a SPI NOR erase type
+ * @erase:     pointer to a structure that describes a SPI NOR erase type
+ */
+void spi_nor_mask_erase_type(struct spi_nor_erase_type *erase)
+{
+       erase->size = 0;
+}
+
 /**
  * spi_nor_init_uniform_erase_map() - Initialize uniform erase map
  * @map:               the erase map of the SPI NOR

diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
index 3348e1dd14452604693c483ba9683bf9f6d7c49a..7eb2090b2fdb7132a657e3ff7c6b6ed2ed2d4929 100644 (file)
--- a/drivers/mtd/spi-nor/core.h
+++ b/drivers/mtd/spi-nor/core.h
@@ -538,6 +538,7 @@ void spi_nor_set_pp_settings(struct spi_nor_pp_command *pp, u8 opcode,
 
 void spi_nor_set_erase_type(struct spi_nor_erase_type *erase, u32 size,
                            u8 opcode);
+void spi_nor_mask_erase_type(struct spi_nor_erase_type *erase);
 struct spi_nor_erase_region *
 spi_nor_region_next(struct spi_nor_erase_region *region);
 void spi_nor_init_uniform_erase_map(struct spi_nor_erase_map *map,

diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
index 0ad217e1151f6734ca7ec4c2faa6dbdc8344645f..c787fdacf0a11723f53fc268546e37f8dac2a1ed 100644 (file)
--- a/drivers/mtd/spi-nor/sfdp.c
+++ b/drivers/mtd/spi-nor/sfdp.c
@@ -874,7 +874,7 @@ static int spi_nor_init_non_uniform_erase_map(struct spi_nor *nor,
         */
        for (i = 0; i < SNOR_ERASE_TYPE_MAX; i++)
                if (!(regions_erase_type & BIT(erase[i].idx)))
-                       spi_nor_set_erase_type(&erase[i], 0, 0xFF);
+                       spi_nor_mask_erase_type(&erase[i]);
 
        return 0;
 }
@@ -1088,7 +1088,7 @@ static int spi_nor_parse_4bait(struct spi_nor *nor,
                        erase_type[i].opcode = (dwords[1] >>
                                                erase_type[i].idx * 8) & 0xFF;
                else
-                       spi_nor_set_erase_type(&erase_type[i], 0u, 0xFF);
+                       spi_nor_mask_erase_type(&erase_type[i]);
        }
 
        /*